Ricin is a plant-derived toxin that could potentially be used as a biological weapon. Exposure to even a small dose of the toxin can cause tissue necrosis and general organ failure within several days.

RiVax contains a genetically altered version of a ricin toxin A (RTA) chain containing 2 mutations that inactivate the toxicity of the ricin molecule. A phase 1B clinical trial of an alum-adjuvanted RiVax formulation found that the vaccine provided 100% protection against acute exposure to aerosolized ricin in 12 rhesus macaque (P <.0001). According to the Company, heat stabilization of the vaccine resulted in enhanced stability and the ability to withstand temperatures at least as high as 104 degrees Fahrenheit for up to 1 year.

“We believe that the FDA’s action in granting Fast Track designation validates the unmet medical need that currently exists for a vaccine providing protection against lethal ricin toxin exposure and for the potential key role RiVax can serve as a part of the US Strategic National Stockpile,” said Christopher J. Schaber, PhD, CEO of Soligenix.